Radial seals are in wide use in industry. An example of a type of radial seal is a torodial elastomeric seal often having a circular cross section, or an O-ring, which rests in a groove in one member and provides a sealing contact against another member. Such seals are used for example in the case of a valve stem which is rotatably disposed in valve body or housing. In some instances, the valve stem will have either a shallow supporting groove, or a deeper dovetailed groove which supports the O-ring in an axial location so that it is in sealing contact with an opposed facing surface on the valve body.
In the case of a relatively shallow seal supporting groove, installation of the seal is generally easily facilitated, since the seal needs only to be expanded over the valve stem and slid into position in the shallow groove, so that when it is released it contracts and snaps into place on the seal receiving groove.
However, in the case of a more deep and or a dovetailed seal receiving groove, installation can often be more complex. When the O-ring is expanded and slid over the groove, its natural contraction force is generally insufficient to pull it all the way into a dovetailed groove. Rather, since the seal has a diameter greater than the opening into the dovetailed groove, the seal tends to simply come to rest around the outside opening of the dovetailed groove. The seal then must be forced radially inwards with a sufficient inward compressive force to squeeze it into the groove.
One prior art method of forcing such a seal into such a dovetail groove has been to take a relatively blunt tool such as a crescent shaped dull blade in a file handle and manually use the tool to press on the outside of the O-ring to force it into the dovetailed retaining groove.
When the O-ring is installed using this approach, a user must generally work his way slowly around the circumference of the seal, forcing a small portion of the circumference into the groove with each pressing motion. This method of installation has the drawbacks that it is somewhat cumbersome and labor intensive, as well as being somewhat time consuming. For certain conventional seals in some valves, the process has been known to take 3 to 10 minutes per seal.
Accordingly, there is a need in the art for a radial seal installation tool and method that can conveniently and economically facilitate installation of a radial seal into a dovetailed receiving groove or channel.